title: Evidence for introduction bottleneck and extensive inter-gene pool (Mesoamerica x Andes) hybridization in the European common bean (Phaseolus vulgaris L.) germplasm.
abstract: Common bean diversity within and between Mesoamerican and Andean gene pools was compared in 89 landraces from America and 256 landraces from Europe, to elucidate the effects of bottleneck of introduction and selection for adaptation during the expansion of common bean (Phaseolus vulgaris L.) in Europe. Thirteen highly polymorphic nuclear microsatellite markers (nuSSRs) were used to complement chloroplast microsatellite (cpSSRs) and nuclear markers (phaseolin and Pv-shatterproof1) data from previous studies. To verify the extent of the introduction bottleneck, inter-gene pool hybrids were distinguished from "pure" accessions. Hybrids were identified on the basis of recombination of gene pool specific cpSSR, phaseolin and Pv-shatterproof1 markers with a Bayesian assignments based on nuSSRs, and with STRUCTURE admixture analysis. More hybrids were detected than previously, and their frequency was almost four times larger in Europe (40.2%) than in America (12.3%). The genetic bottleneck following the introduction into Europe was not evidenced in the analysis including all the accessions, but it was significant when estimated only with "pure" accessions, and five times larger for Mesoamerican than for Andean germplasm. The extensive inter-gene pool hybridization generated a large amount of genotypic diversity that mitigated the effects of the bottleneck that occurred when common bean was introduced in Europe. The implication for evolution and the advantages for common bean breeding are discussed.
authors.affiliation: Scuola di Scienze Agrarie, Forestali, Alimentari ed Ambientali, Università degli Studi della Basilicata, Potenza, Italy.
authors.forename: Tania
authors.initials: T
authors.lastname: Gioia
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Logozzo
authors.forename: Giovanna
authors.initials: G
authors.lastname: Attene
authors.forename: Elisa
authors.initials: E
authors.lastname: Bellucci
authors.forename: Stefano
authors.initials: S
authors.lastname: Benedettelli
authors.forename: Valeria
authors.initials: V
authors.lastname: Negri
authors.forename: Roberto
authors.initials: R
authors.lastname: Papa
authors.forename: Pierluigi
authors.initials: P
authors.lastname: Spagnoletti Zeuli
mesh_terms: D018744:DNA, Plant / Q000235:genetics; D005788:Gene Pool; D014644:Genetic Variation; D023281:Genomics; D060005:Genotyping Techniques; D006824:Hybridization, Genetic; D018895:Microsatellite Repeats / Q000235:genetics; D027805:Phaseolus / Q000166:cytology* / Q000235:genetics*; D011995:Recombination, Genetic; D013045:Species Specificity
chemical_list: D018744:DNA, Plant